Complementing a network-switching function, insula’s role in interoception (Craig et al., 2002; Craig, 2009), and, by extension, drug addiction (Naqvi and Bechara, 2009, 2010), has been of substantial recent interest. Interoception refers to the monitoring of internal bodily states to maintain or procure homeostasis, possibly via rousing the organism through affective, motivational, and attentional alterations. The insula contains multiple subregions that have been parsed along a posterior-to-anterior gradient (Craig 2009), such that more posterior regions have been related to primary interoceptive operations and more anterior regions associated with affective and cognitive processes. Exploration of these insular functional subdivisions using rsFC analyses has generally bolstered such a conceptualization (Cauda et al., 2011; Deen et al., 2011; Taylor et al., 2009). Accordingly, multiple perspectives have emerged relating insula with subjective drug urges (Naqvi and Bechara, 2009; Garavan et al., 2010), impaired behavioral monitoring (Goldstein et al., 2009), and maladaptive decision-making (Paulus et al., 2007) in drug addicts. Naqvi and Bechara (2010) have elucidated a rather thorough model of insula’s interoceptive role at multiple stages of the addiction cycle (e.g., drug-taking, -withdrawal, -urges).
